JPH066479Y2 - Automatic light control desk lamp - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a desk lamp that automatically adjusts light intensity according to ambient brightness.

[Conventional technology]

In general, a lighting device used for working on a desk or reading a book is required to have high luminous intensity. For this reason, conventionally, some lighting devices such as a table lamp are provided with a dimming unit so as to obtain a required luminous intensity.

For example, the desk lamp disclosed in Japanese Utility Model Laid-Open No. 58-147192 has a lamp 23 as shown in FIG.
However, the intensity of the light received by the light receiving element 22 provided in the fixture 21 is adjusted so that the brightness of the light receiving surface 25 does not change by changing the height of the lamp 23. A dimming unit that changes the luminous intensity of the lamp 23 according to the brightness is provided.

As the dimming means, for example, as shown in FIG. 7, a diac D, a triac T, a variable resistor Rv, a capacitor C ₃ , a lamp 23, and a commercial power source 24 are well known. In such a configuration, when the charging current flows into the capacitor C ₃ via the variable resistor Rv, the terminal voltage of the capacitor C ₃ increases at a phase slightly behind the voltage of the commercial power supply 24. Diac D
Conducts when the terminal voltage of the capacitor C ₃ reaches the breakover voltage of the diac D, and at this time, the electric charge charged in the capacitor C ₃ is discharged through the gate of the triac T to conduct the triac T. That is, by changing the resistance value of the variable resistor Rv changing the charging time constant of the capacitor C _3, by adjusting the timing capacitor C ₃ is discharged to charge commercial power by controlling the gate phase angle of the triac T The phase of 24 is controlled to enable the dimming of the lamp 23.

However, such a circuit configuration has a drawback in that not only dimming cannot be automatically performed, but also a hysteresis phenomenon occurs. Therefore, the light control means shown in FIG. 8 is based on the light control means shown in FIG. 7, and instead of the variable resistor Rv, the light receiving element 22 (phototransistor).
The lamp 2 is automatically provided according to the output of the light receiving element 22.
The dimming of 3 is performed, and the hysteresis of the circuit is reduced to improve the phase control characteristic.

With such a light control unit, the lamp 23 is moved away from the light receiving surface 25, and when the light received by the light receiving element 22 becomes weaker, the luminous intensity of the lamp 23 is increased and the lamp 23 is brought closer to the light receiving surface 25 so that the light receiving element 22 receives light. Lamp 2 becomes stronger
Dimming was performed so that the brightness of 3 was reduced.

[Problems to be solved by the device]

The brightness of the room is not only the difference in brightness between daytime and nighttime,
It may be affected by the outdoor brightness due to the weather, etc.
It cannot be said that the situation is always constant. However, in the above-described conventional automatic light control type desk lamp, although the brightness of the light receiving surface 25 can be kept substantially constant by changing the light intensity of the lamp 23, the light control is performed regardless of the ambient brightness. However, there is a difference between the brightness of the light-receiving surface 25 and the surrounding brightness. If this difference is small, it does not matter,
If the light-receiving surface 25 becomes too bright or too dark as compared with the surroundings, the eyeball feels the difference and increases the movement of the pupil, which causes a problem that the eyes are easily tired.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, an automatic light control type desk lamp according to claim 1 has a main light source that illuminates a light-receiving surface with a certain luminous intensity, an auxiliary light source that illuminates the rear side of the desk lamp, and a surrounding area. A light receiving element that senses the brightness of the light, and a dimming unit that reduces the light intensity of the auxiliary light source when the surroundings are bright by the output of the light receiving element while increasing the light intensity of the auxiliary power source when the surroundings are dark. It is characterized by being.

In order to solve the above-mentioned problems, an automatic light control type desk lamp according to a second aspect uses a light source that illuminates a light receiving surface, a light receiving element that senses ambient brightness, and an output of the light receiving element. When the ambient brightness is above a certain level, the light intensity of the light source is increased, while when the ambient brightness is below a certain level, the light intensity of the light source is decreased and the light intensity of the light source is adjusted in advance. It is characterized in that it is provided with a dimming means for performing within a set fixed range.

[Action]

According to the structure of the first aspect, when the surrounding becomes bright, the light receiving element senses it, and the dimming means reduces the luminous intensity of the auxiliary light source by the output signal of the light receiving element to make the back of the table lamp bright. On the contrary, when the surroundings become dark, the dimming unit increases the luminous intensity of the auxiliary light source to light the back of the table lamp.

As described above, the light control unit adjusts the brightness of the light receiving surface by adjusting the auxiliary light source according to the ambient brightness while keeping the brightness of the light receiving surface constant by the main light source. Since the difference in the brightness is reduced by bringing it closer to the height, it is possible to reduce the movement of the pupil and reduce eye fatigue.

According to the structure of the second aspect, when the surrounding becomes bright, the light receiving element senses it, and the dimming means increases the luminous intensity of the light source and makes the light receiving surface bright by the output signal of the light receiving element. On the contrary, when the surroundings become dark, the light control unit reduces the light intensity of the light source to darken the light receiving surface.

In this way, the dimming unit dims the light source according to the brightness of the surroundings to bring the brightness of the light-receiving surface close to the brightness of the surroundings, thereby reducing the difference in brightness. The movement can be reduced and eye fatigue can be reduced.

Further, since the light control means adjusts the light intensity of the light source within a preset constant range, it is possible to secure the minimum required brightness on the light receiving surface even when the surroundings become dark.

[Embodiment according to claim 1] An embodiment according to claim 1 of the present invention is shown in Figs.
If not explained based on the drawings, it is as follows.

As shown in FIG. 1, the automatic dimming-type table lamp has an outer appearance composed of a base portion 1, a support 2, a head 3, and shades 4 and 5. A lamp 6 as a main light source is attached to the bottom surface of the head 3, and an auxiliary lamp 7 as an auxiliary light source is attached to the inside of the shade 5 on the side surface of the head 3. Further, a light receiving element 8 is provided on the upper surface of the head 3 so as to sense the ambient brightness. The base unit 1 is provided with an impedance control circuit 10 and a dimming circuit 11.

As shown in FIG. 2, the dimming means supplies the output signal from the light receiving element 8 to the dimming circuit 11 via the impedance control circuit 10, and the dimming circuit 11 causes the commercial power supply 12 to operate.
Is controlled so that the auxiliary lamp 7 is dimmed.

The impedance control circuit 10 changes the impedance according to the magnitude of the output signal from the light receiving element 8 to control the magnitude of the signal supplied to the dimming circuit 11.

Since the lamp 6 is directly supplied with electric power from the commercial power source 12 without passing through the dimming circuit 11, the lamp 6 always keeps a constant luminous intensity. In addition, between the commercial power source 12 and the lamp 6,
An ON / OFF switch SW for turning on and off the lamp 6 is provided.

In the above configuration, the ON / OFF switch SW provided between the commercial power source 12 and the lamp 6 is turned on to turn on the lamp 6.
After illuminating, the light receiving element 8 that senses the ambient brightness
A signal having a magnitude corresponding to the brightness is output. The impedance control circuit 10 adjusts the magnitude of the signal and supplies it to the dimming circuit 11, and the dimming circuit 11 supplies the commercial power source 12
The auxiliary lamp 7 is dimmed by controlling the phase of. The auxiliary lamp 7 reduces the light intensity and darkens the wall surface 13 when the surroundings become bright by the light control circuit 11, and conversely increases the light intensity and brightens the wall surface 13 when the surroundings become dark.

In this way, the light control unit controls the auxiliary lamp 7 in accordance with the ambient brightness to reduce the difference between the brightness of the wall surface 13 and the brightness of the light receiving surface 9. Further, since the light control by the light control means is performed only for the auxiliary lamp 7, the light receiving surface 9 is received by the lamp 6 even when the surroundings become extremely dark.
Of course, the brightness can be kept constant.

[Embodiment according to claim 2] An embodiment according to claim 2 of the present invention is shown in Figs.
It will be described below with reference to the drawings. A member having the same function as that of the embodiment according to claim 1 is
The same reference numerals are added.

As shown in FIG. 3, the automatic dimming-type table lamp has an outer appearance composed of a base portion 1, a support 2, a head 3, and a shade 4. A lamp 6 as a light source is attached to the bottom surface of the head 3, and a light receiving element 8 is provided on the top surface of the head 3. The base unit 1 is provided with a sympathy dance control circuit 10 and a dimming circuit 11.

As shown in FIG. 4, the dimming means supplies the output signal from the light receiving element 8 to the dimming circuit 11 via the impedance control circuit 10, and the dimming circuit 11 causes the commercial power supply 12 to operate.
Is controlled so that the light of the lamp 6 is controlled.

The impedance control circuit 10 changes the impedance according to the magnitude of the output signal from the light receiving element 8 to adjust the magnitude of the signal supplied to the dimming circuit 11. In the impedance control circuit 10, the lamp 6
The range in which the output signal changes is set in advance so that the light is dimmed within a certain range.

In the above-mentioned configuration, in order to perform the dimming of the lamp 6, the fourth
As shown in the figure, the light receiving element 8 that senses the ambient brightness
Outputs a signal having a magnitude corresponding to the brightness, and the impedance control circuit 10 adjusts the magnitude of this output signal. The dimming circuit 11 controls the phase of the commercial power supply 12 according to the output signal of the impedance control circuit 10, and when the ambient brightness is brighter than a certain level, the light intensity of the lamp 6 is increased and the light receiving surface 9 is illuminated. On the contrary, when the surrounding brightness is darker than a certain level, the light intensity of the lamp 6 is decreased to darken the light receiving surface 9.

In this way, the light control means controls the lamp 6 to reduce the difference between the brightness of the light receiving surface 9 and the ambient brightness. Further, since the light control by the light control means is performed within a preset constant range, the minimum brightness required on the light receiving surface 9 can be secured even when the surroundings become extremely dark. Of course.

[Effect of device]

As described above, the automatic light control type desk lamp according to claim 1 senses ambient brightness by a main light source that illuminates the light-receiving surface with a constant luminous intensity, an auxiliary light source that illuminates the back of the desk lamp. And a dimming unit that reduces the luminous intensity of the auxiliary light source when the surroundings are bright and increases the luminous intensity of the auxiliary power source when the surroundings are dark by the output of the photosensitive element.

As a result, the auxiliary light source is dimmed according to the brightness so that the difference in brightness between the back of the desk lamp and the light-receiving surface is reduced, so that the movement of the pupil is reduced and eye fatigue can be reduced. Play.

As described above, the automatic light control type desk lamp according to claim 2 has a light source that illuminates the light-receiving surface, a light-receiving element that senses the ambient brightness, and an output of the light-receiving element to determine the ambient brightness. Is higher than a certain level, the luminous intensity of the light source is increased, while when the ambient brightness is less than a certain level, the luminous intensity of the light source is decreased, and the luminous intensity adjustment of the light source is set to a predetermined level. It is the structure provided with the light control means performed within the range.

As a result, the light source is dimmed so as to reduce the difference between the ambient brightness and the light receiving surface brightness while maintaining the brightness within a preset fixed range, so that it is suitable for work and reading. The effect is that the required brightness can be secured, the movement of the pupil is reduced, and eye fatigue can be reduced.

[Brief description of drawings]

1 and 2 show an embodiment of an automatic dimming table lamp according to the invention of claim 1, and FIG. 1 is an external view showing the entire structure of the automatic dimming table lamp. FIG. 2 is a side view and FIG. 2 is a block diagram for explaining the structure of the light control means. FIGS. 3 to 5 show an embodiment of an automatic dimming table lamp according to the invention of claim 2, and FIG. 3 is an external view showing the entire structure of the automatic dimming table lamp. FIG. 4 is a side view, FIG. 4 is a block diagram illustrating the structure of the light control means, and FIG. 5 is a graph showing the relationship between the ambient brightness and the luminous intensity of the lamp. 6 to 8 show a conventional example.
FIG. 7 is an external view showing the overall configuration of the automatic light control type desk lamp, FIG. 7 is a circuit diagram showing the basic configuration of the light control means, and FIG. 8 is a circuit diagram showing the configuration of the light control means. 6 is a lamp, 7 is an auxiliary lamp, 8 is a light receiving element, 10 is an impedance control circuit, and 11 is a dimming circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-51-185893 (JP, A) JP-A-1-105499 (JP, A) Actual development 61-85094 (JP, U) Actual development 62- 5504 (JP, U) Actual opening 60-19198 (JP, U) Actual opening Sho 49-68277 (JP, U) Actual opening Sho 62-70396 (JP, U) Actual opening Sho 58-147192 (JP, U) Actual public Sho 63-1372 (JP, Y2)

Claims (2)

[Scope of utility model registration request] 1. A main light source that illuminates a light-receiving surface with a constant luminous intensity, an auxiliary light source that illuminates the back of a desk lamp, a light-receiving element that senses ambient brightness, and an output of the light-receiving element causes An automatic dimming table lamp, comprising: a dimming unit that reduces the luminous intensity of the auxiliary light source when it is bright and increases the luminous intensity of the auxiliary power source when the surroundings are dark. 2. A light source that illuminates a light-receiving surface, a light-receiving element that senses ambient brightness, and an output of the light-receiving element increases the luminous intensity of the light source when the ambient brightness is above a certain level. On the other hand, when the surrounding brightness is below a certain level, the light intensity of the light source is reduced, and a dimming means for adjusting the light intensity of the light source within a preset constant range is provided. Characteristic automatic light control desk lamp.